1. Field of the Invention
The present invention relates to a structure of a connector for IC card to be used as a storage medium in a personal computer or the like. Particularly, the invention is concerned with a grounding structure of shielding plates.
2. Description of the Prior Art
As an expanded memory for a personal computer there generally is employed a connector for IC card, and as a storage medium for such an IC card connector, an IC card has come to be used widely. On the IC card is mounted an IC (integrated circuit) for the storage of various information pieces, and for preventing a malfunction of the IC, a dimple (a grounding piece) for grounding is provided on a peripheral surface of the IC card, which dimple functions to prevent the influence of a bounce noise generated within the circuit or an external noise entering from the exterior.
It is known that also on the IC card connector side for the loading of such an IC card with dimple there is mounted a shielding plate for preventing the influence of such bounce noise or external noise as referred to above.
For example, according to a known structure of a shielding plate used in an IC card connector, an electrically conductive metallic plate as a shielding plate is disposed on either an upper surface side or a lower surface side of a connector housing. This shielding plate is disposed so as to cover upper surfaces of plural contact terminals fixed to the connector housing and is centrally formed with plural contact pieces capable of contacting a dimple of an IC card.
Further, at both ends of the shielding plate are formed grounding portions capable of contacting a grounding pattern formed on a circuit board onto which the connector housing is mounted and fixed. By forming screw inserting holes respectively in the grounding portions and by fixing the grounding portions to the circuit board with screws and nuts there are effected both grounding of the shielding plate to the grounding pattern and fixing of the housing to the circuit board.
However, in the above conventional shielding plate structure for an IC card connector, both end portions of the shielding plate are extended, then screw inserting holes are formed respectively in the thus-extended portions, and the grounding portions thus formed with the screw inserting holes are screwed to the circuit board with screws and nuts and are thereby fixed onto the circuit board. However, since there is no swivel stop for the nuts, it is necessary to hold down each nut with a jig or the like during the screw tightening work, resulting in that the same work becomes troublesome.
Both end portions of the housing may be partially cut out along the shape (hexagon) of each nut to form swivel-stop portions for the nuts, but resinous swivel stops are apt to slip and low in strength, thus giving rise to problems in machinability and assembling reliability.